1 code implementation • 1 Nov 2024 • Yunshi Wen, Tengfei Ma, Tsui-Wei Weng, Lam M. Nguyen, Anak Agung Julius
By introducing a novel representation for time-series data, we forge a connection between the latent space of VQShape and shape-level features.
no code implementations • 29 Oct 2024 • Quoc Tran-Dinh, Trang H. Tran, Lam M. Nguyen
This paper aims at developing novel shuffling gradient-based methods for tackling two classes of minimax problems: nonconvex-linear and nonconvex-strongly concave settings.
1 code implementation • 22 Oct 2024 • Anthony Baez, Wang Zhang, Ziwen Ma, Subhro Das, Lam M. Nguyen, Luca Daniel
Physics-informed neural networks (PINNs) incorporate physical laws into their training to efficiently solve partial differential equations (PDEs) with minimal data.
no code implementations • 14 Jun 2024 • Quan M. Tran, Suong N. Hoang, Lam M. Nguyen, Dzung Phan, Hoang Thanh Lam
We pretrained FMs on this curated data, benchmarked various learning methods on these datasets, and released the pretrained models along with leaderboards for future comparative studies.
no code implementations • 5 Mar 2024 • Trang H. Tran, Quoc Tran-Dinh, Lam M. Nguyen
The Stochastic Gradient Descent method (SGD) and its stochastic variants have become methods of choice for solving finite-sum optimization problems arising from machine learning and data science thanks to their ability to handle large-scale applications and big datasets.
1 code implementation • 21 Dec 2023 • Anh Duc Nguyen, Tuan Dung Nguyen, Quang Minh Nguyen, Hoang H. Nguyen, Lam M. Nguyen, Kim-Chuan Toh
This paper studies the Partial Optimal Transport (POT) problem between two unbalanced measures with at most $n$ supports and its applications in various AI tasks such as color transfer or domain adaptation.
1 code implementation • 16 Dec 2023 • Wang Zhang, Ziwen Ma, Subhro Das, Tsui-Wei Weng, Alexandre Megretski, Luca Daniel, Lam M. Nguyen
Neural networks are powerful tools in various applications, and quantifying their uncertainty is crucial for reliable decision-making.
no code implementations • 21 Nov 2023 • Trang H. Tran, Lam M. Nguyen, Kyongmin Yeo, Nam Nguyen, Roman Vaculin
Foundation models have recently gained attention within the field of machine learning thanks to its efficiency in broad data processing.
no code implementations • 20 Nov 2023 • Quang Minh Nguyen, Lam M. Nguyen, Subhro Das
Multivariate time series (MTS) analysis prevails in real-world applications such as finance, climate science and healthcare.
no code implementations • 11 Oct 2023 • Linbo Liu, Trong Nghia Hoang, Lam M. Nguyen, Tsui-Wei Weng
The second approach introduces a post-processing method EsbRS which greatly improves the robustness certificate based on building model ensembles.
no code implementations • 21 Jul 2023 • Toan N. Nguyen, Phuong Ha Nguyen, Lam M. Nguyen, Marten van Dijk
In this paper, we propose {\em a new ALC and provide rigorous DP proofs for both BC and ALC}.
1 code implementation • 11 Jun 2023 • Duy A. Nguyen, Trang H. Tran, Huy Hieu Pham, Phi Le Nguyen, Lam M. Nguyen
In this work, we investigate the time series representation learning problem using self-supervised techniques.
no code implementations • 1 Jun 2023 • Trang H. Tran, Lam M. Nguyen, Kyongmin Yeo, Nam Nguyen, Dzung Phan, Roman Vaculin, Jayant Kalagnanam
Time series forecasting using historical data has been an interesting and challenging topic, especially when the data is corrupted by missing values.
2 code implementations • 12 Apr 2023 • Tuomas Oikarinen, Subhro Das, Lam M. Nguyen, Tsui-Wei Weng
Motivated by these challenges, we propose Label-free CBM which is a novel framework to transform any neural network into an interpretable CBM without labeled concept data, while retaining a high accuracy.
1 code implementation • 11 Feb 2023 • Wang Zhang, Tsui-Wei Weng, Subhro Das, Alexandre Megretski, Luca Daniel, Lam M. Nguyen
Deep neural networks (DNN) have shown great capacity of modeling a dynamical system; nevertheless, they usually do not obey physics constraints such as conservation laws.
no code implementations • 12 Dec 2022 • Marten van Dijk, Phuong Ha Nguyen, Toan N. Nguyen, Lam M. Nguyen
Classical differential private DP-SGD implements individual clipping with random subsampling, which forces a mini-batch SGD approach.
no code implementations • 21 Jun 2022 • Trang H. Tran, Lam M. Nguyen, Katya Scheinberg
In this work, we investigate the optimization aspects of the queueing model as a RL environment and provide insight to learn the optimal policy efficiently.
no code implementations • 8 Feb 2022 • Quang Minh Nguyen, Hoang H. Nguyen, Yi Zhou, Lam M. Nguyen
In this paper, we propose a novel algorithm based on Gradient Extrapolation Method (GEM-UOT) to find an $\varepsilon$-approximate solution to the UOT problem in $O\big( \kappa \log\big(\frac{\tau n}{\varepsilon}\big) \big)$ iterations with $\widetilde{O}(n^2)$ per-iteration cost, where $\kappa$ is the condition number depending on only the two input measures.
no code implementations • 7 Feb 2022 • Lam M. Nguyen, Trang H. Tran, Marten van Dijk
How and under what assumptions is guaranteed convergence to a \textit{global} minimum possible?
no code implementations • 7 Feb 2022 • Nhan H. Pham, Lam M. Nguyen, Jie Chen, Hoang Thanh Lam, Subhro Das, Tsui-Wei Weng
In recent years, a proliferation of methods were developed for cooperative multi-agent reinforcement learning (c-MARL).
1 code implementation • 7 Feb 2022 • Trang H. Tran, Katya Scheinberg, Lam M. Nguyen
This rate is better than that of any other shuffling gradient methods in convex regime.
no code implementations • 10 Dec 2021 • Connor Lawless, Jayant Kalagnanam, Lam M. Nguyen, Dzung Phan, Chandra Reddy
To solve our formulation we propose a two phase approach where we first initialize clusters and polytopes using alternating minimization, and then use coordinate descent to boost clustering performance.
1 code implementation • NeurIPS 2021 • Yilan Chen, Wei Huang, Lam M. Nguyen, Tsui-Wei Weng
Therefore, in this work, we propose to establish the equivalence between NN and SVM, and specifically, the infinitely wide NN trained by soft margin loss and the standard soft margin SVM with NTK trained by subgradient descent.
1 code implementation • NeurIPS 2021 • Hoang Thanh Lam, Gabriele Picco, Yufang Hou, Young-suk Lee, Lam M. Nguyen, Dzung T. Phan, Vanessa López, Ramon Fernandez Astudillo
In many machine learning tasks, models are trained to predict structure data such as graphs.
Ranked #2 on AMR Parsing on LDC2020T02 (using extra training data)
no code implementations • 29 Sep 2021 • Nhan Pham, Lam M. Nguyen, Jie Chen, Thanh Lam Hoang, Subhro Das, Tsui-Wei Weng
In recent years, a proliferation of methods were developed for multi-agent reinforcement learning (MARL).
no code implementations • 29 Sep 2021 • Lam M. Nguyen, Trang H. Tran, Marten van Dijk
How and under what assumptions is guaranteed convergence to a \textit{global} minimum possible?
no code implementations • 29 Sep 2021 • Wang Zhang, Lam M. Nguyen, Subhro Das, Pin-Yu Chen, Sijia Liu, Alexandre Megretski, Luca Daniel, Tsui-Wei Weng
In verification-based robust training, existing methods utilize relaxation based methods to bound the worst case performance of neural networks given certain perturbation.
1 code implementation • 5 Mar 2021 • Quoc Tran-Dinh, Nhan H. Pham, Dzung T. Phan, Lam M. Nguyen
These new algorithms can handle statistical and system heterogeneity, which are the two main challenges in federated learning, while achieving the best known communication complexity.
no code implementations • 17 Feb 2021 • Marten van Dijk, Nhuong V. Nguyen, Toan N. Nguyen, Lam M. Nguyen, Phuong Ha Nguyen
Generally, DP-SGD is $(\epsilon\leq 1/2,\delta=1/N)$-DP if $\sigma=\sqrt{2(\epsilon +\ln(1/\delta))/\epsilon}$ with $T$ at least $\approx 2k^2/\epsilon$ and $(2/e)^2k^2-1/2\geq \ln(N)$, where $T$ is the total number of rounds, and $K=kN$ is the total number of gradient computations where $k$ measures $K$ in number of epochs of size $N$ of the local data set.
no code implementations • 1 Jan 2021 • Kaleel Mahmood, Phuong Ha Nguyen, Lam M. Nguyen, Thanh V Nguyen, Marten van Dijk
Based on our study of these defenses, we develop three contributions.
no code implementations • 24 Nov 2020 • Trang H. Tran, Lam M. Nguyen, Quoc Tran-Dinh
When the shuffling strategy is fixed, we develop another new algorithm that is similar to existing momentum methods, and prove the same convergence rates for this algorithm under the $L$-smoothness and bounded gradient assumptions.
no code implementations • NeurIPS 2020 • Haoran Zhu, Pavankumar Murali, Dzung T. Phan, Lam M. Nguyen, Jayant R. Kalagnanam
Several recent publications report advances in training optimal decision trees (ODT) using mixed-integer programs (MIP), due to algorithmic advances in integer programming and a growing interest in addressing the inherent suboptimality of heuristic approaches such as CART.
no code implementations • 27 Oct 2020 • Marten van Dijk, Nhuong V. Nguyen, Toan N. Nguyen, Lam M. Nguyen, Quoc Tran-Dinh, Phuong Ha Nguyen
We consider big data analysis where training data is distributed among local data sets in a heterogeneous way -- and we wish to move SGD computations to local compute nodes where local data resides.
no code implementations • 20 Aug 2020 • Deyi Liu, Lam M. Nguyen, Quoc Tran-Dinh
In this note we propose a new variant of the hybrid variance-reduced proximal gradient method in [7] to solve a common stochastic composite nonconvex optimization problem under standard assumptions.
no code implementations • 17 Jul 2020 • Marten van Dijk, Nhuong V. Nguyen, Toan N. Nguyen, Lam M. Nguyen, Quoc Tran-Dinh, Phuong Ha Nguyen
The feasibility of federated learning is highly constrained by the server-clients infrastructure in terms of network communication.
no code implementations • NeurIPS 2020 • Quoc Tran-Dinh, Deyi Liu, Lam M. Nguyen
This problem class has several computational challenges due to its nonsmoothness, nonconvexity, nonlinearity, and non-separability of the objective functions.
no code implementations • 24 Mar 2020 • Thinh T. Doan, Lam M. Nguyen, Nhan H. Pham, Justin Romberg
Motivated by broad applications in reinforcement learning and machine learning, this paper considers the popular stochastic gradient descent (SGD) when the gradients of the underlying objective function are sampled from Markov processes.
1 code implementation • 1 Mar 2020 • Nhan H. Pham, Lam M. Nguyen, Dzung T. Phan, Phuong Ha Nguyen, Marten van Dijk, Quoc Tran-Dinh
We propose a novel hybrid stochastic policy gradient estimator by combining an unbiased policy gradient estimator, the REINFORCE estimator, with another biased one, an adapted SARAH estimator for policy optimization.
no code implementations • 19 Feb 2020 • Lam M. Nguyen, Quoc Tran-Dinh, Dzung T. Phan, Phuong Ha Nguyen, Marten van Dijk
We also study uniformly randomized shuffling variants with different learning rates and model assumptions.
1 code implementation • ICML 2020 • Quoc Tran-Dinh, Nhan H. Pham, Lam M. Nguyen
In the expectation case, we establish $\mathcal{O}(\varepsilon^{-2})$ iteration-complexity to achieve a stationary point in expectation and estimate the total number of stochastic oracle calls for both function value and its Jacobian, where $\varepsilon$ is a desired accuracy.
no code implementations • 3 Oct 2019 • Kaleel Mahmood, Phuong Ha Nguyen, Lam M. Nguyen, Thanh Nguyen, Marten van Dijk
We argue that our defense based on buffer zones offers significant improvements over state-of-the-art defenses.
no code implementations • 8 Jul 2019 • Quoc Tran-Dinh, Nhan H. Pham, Dzung T. Phan, Lam M. Nguyen
We introduce a new approach to develop stochastic optimization algorithms for a class of stochastic composite and possibly nonconvex optimization problems.
no code implementations • 15 May 2019 • Quoc Tran-Dinh, Nhan H. Pham, Dzung T. Phan, Lam M. Nguyen
We introduce a hybrid stochastic estimator to design stochastic gradient algorithms for solving stochastic optimization problems.
1 code implementation • 15 Feb 2019 • Nhan H. Pham, Lam M. Nguyen, Dzung T. Phan, Quoc Tran-Dinh
We also specify the algorithm to the non-composite case that covers existing state-of-the-arts in terms of complexity bounds.
no code implementations • 22 Jan 2019 • Lam M. Nguyen, Phuong Ha Nguyen, Dzung T. Phan, Jayant R. Kalagnanam, Marten van Dijk
This paper has some inconsistent results, i. e., we made some failed claims because we did some mistakes for using the test criterion for a series.
no code implementations • 22 Jan 2019 • Lam M. Nguyen, Marten van Dijk, Dzung T. Phan, Phuong Ha Nguyen, Tsui-Wei Weng, Jayant R. Kalagnanam
The total complexity (measured as the total number of gradient computations) of a stochastic first-order optimization algorithm that finds a first-order stationary point of a finite-sum smooth nonconvex objective function $F(w)=\frac{1}{n} \sum_{i=1}^n f_i(w)$ has been proven to be at least $\Omega(\sqrt{n}/\epsilon)$ for $n \leq \mathcal{O}(\epsilon^{-2})$ where $\epsilon$ denotes the attained accuracy $\mathbb{E}[ \|\nabla F(\tilde{w})\|^2] \leq \epsilon$ for the outputted approximation $\tilde{w}$ (Fang et al., 2018).
no code implementations • 18 Dec 2018 • Tsui-Wei Weng, Pin-Yu Chen, Lam M. Nguyen, Mark S. Squillante, Ivan Oseledets, Luca Daniel
With deep neural networks providing state-of-the-art machine learning models for numerous machine learning tasks, quantifying the robustness of these models has become an important area of research.
no code implementations • 25 Nov 2018 • Lam M. Nguyen, Katya Scheinberg, Martin Takáč
We develop and analyze a variant of the SARAH algorithm, which does not require computation of the exact gradient.
no code implementations • 10 Nov 2018 • Lam M. Nguyen, Phuong Ha Nguyen, Peter Richtárik, Katya Scheinberg, Martin Takáč, Marten van Dijk
We show the convergence of SGD for strongly convex objective function without using bounded gradient assumption when $\{\eta_t\}$ is a diminishing sequence and $\sum_{t=0}^\infty \eta_t \rightarrow \infty$.
no code implementations • NeurIPS 2019 • Phuong Ha Nguyen, Lam M. Nguyen, Marten van Dijk
We study the convergence of Stochastic Gradient Descent (SGD) for strongly convex objective functions.
no code implementations • 9 Oct 2018 • Marten van Dijk, Lam M. Nguyen, Phuong Ha Nguyen, Dzung T. Phan
We study Stochastic Gradient Descent (SGD) with diminishing step sizes for convex objective functions.
no code implementations • ICML 2018 • Lam M. Nguyen, Phuong Ha Nguyen, Marten van Dijk, Peter Richtárik, Katya Scheinberg, Martin Takáč
In (Bottou et al., 2016), a new analysis of convergence of SGD is performed under the assumption that stochastic gradients are bounded with respect to the true gradient norm.
no code implementations • 18 Jan 2018 • Lam M. Nguyen, Nam H. Nguyen, Dzung T. Phan, Jayant R. Kalagnanam, Katya Scheinberg
In this paper, we consider a general stochastic optimization problem which is often at the core of supervised learning, such as deep learning and linear classification.
no code implementations • 20 May 2017 • Lam M. Nguyen, Jie Liu, Katya Scheinberg, Martin Takáč
In this paper, we study and analyze the mini-batch version of StochAstic Recursive grAdient algoritHm (SARAH), a method employing the stochastic recursive gradient, for solving empirical loss minimization for the case of nonconvex losses.
no code implementations • ICML 2017 • Lam M. Nguyen, Jie Liu, Katya Scheinberg, Martin Takáč
In this paper, we propose a StochAstic Recursive grAdient algoritHm (SARAH), as well as its practical variant SARAH+, as a novel approach to the finite-sum minimization problems.